Rearrangement Reactions Leading to Optically Active α,α-Disubstituted Primary Allylamines
Synthetic routes to α,α-disubstituted allylamines have been examined. Racemic compounds were conveniently prepared by thermal Overman rearrangements of primary allylic alcohols with trisubstituted double bonds, but rearrangement of these substrates using
Highly enantioselective iridium-catalyzed hydrogenation of α,β-unsaturated esters
α,β-Unsaturated esters have been employed as substrates in iridium-catalyzed asymmetric hydrogenation. Full conversions and good to excellent enantioselectivities (up to 99 % ee) were obtained for a broad range of substrates with both aromatic- and aliphatic substituents on the prochiral carbon. The hydrogenated products are highly useful as building blocks in the synthesis of a variety of natural products and pharmaceuticals. Asymmetric hydrogenation: A variety of α,β-unsaturated esters were hydrogenated with high enantioselectivities (see scheme). The hydrogenated products have been used in synthetic transformations as well as in formal total syntheses. Copyright
Li, Jia-Qi,Quan, Xu,Andersson, Pher G.
supporting information
p. 10609 - 10616
(2012/11/07)
Esterase-mediated synthesis of optically active GABA analogues containing a stereogenic all-carbon quaternary carbon atom
Esterase from Horse Liver (HLAP) was able to hydrolyze a series of linear and cyclic β,β-dialkyl-γ-nitroesters, in spite of the well-known reluctance of hydrolytic enzymes to recognize and transform hindered substrates, such as those possessing a stereoge
Stabilization and activation of dienolates with germanium and tin. Stero- and regioselective aldol reactions, regioselective coupling reactions, and regioselective synthesis of amino acid derivatives
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Yamamoto,Hatsuya,Yamada
p. 3118 - 3128
(2007/10/02)
Carbon-Carbon Bond Formation at the γ-position of Dienolates via the Palladium Catalysed Coupling of the Tin Masked Dienolates
The palladium catalysed coupling reaction of the tin masked dienolate (2) with organic halides takes place at the position substituted by tin, thereby providing a new method for C-C bond formation at the γ-position of dienolates.